Such winches are well-known and specifically are used on a large scale in yachting, for winding a sheet on the bollard, which takes place either manually by means of a crank which can be placed in an appropriate hole in the vicinity of the upper surface of the bollard, and by means of which the driving gear can be rotated, or automatically by means of a motor coupled to the driving gear. As the hauling of a sheet by means of the winch requires very substantial forces, the prior art has developed winches arranged to rotate at different speeds, so that, at a first speed, one revolution of the driving gear corresponds to the largest displacement of the sheet by means of the winch, and each next speed corresponds to a shorter displacement of the sheet, so that the force required for tautening the sheet decreases with subsequent winch speeds. In the case of a two-speed winch, the arrangement is generally such that when the driving gear is rotated in a first direction the bollard rotates at the first speed, and when the direction of rotation of the driving gear is reversed, the bollard rotates at the second speed.
In prior art three-speed winches, the transition between successive speeds is also effected by reversing the direction of rotation of the driving gear, but at some moment during use at successive speeds, it is necessary to manually operate a lever, a button, or the like, for the winch to be successively operated at the three speeds.
Operating a button, lever, or the like, however, is an additional operation which, for example during racing, but also in the case of heavy weather, may be highly undesirable, because it tends to distract the yachtman's attention, who would, in addition, in many cases like to have the hand required for turning the button or the like free either to rotate the winch cranks with both hands, or for other work. Accordingly, there is a great need of a three-speed winch in which the transition between the different speeds is effected fully automatically just by changing the direction of rotation of the driving gear, without the need of operating the winch in any other way.